Prophylactic devices for the prevention of sexual disease, as used in large numbers throughout the world, are most often made of natural rubber latex material in very thin wall thicknesses ranging from 0.3 millimeters (30 micrometers) to 0.7 millimeters (70 micrometers). Such very thin membranes of highly elastic natural materials have been found most desirable to minimize interference with active movement during use as well as permitting the users to retain the nerve sensations and experiences during such use.
However, natural rubber material, in such thin wall membranes, does not provide a continuous, impermeable barrier to the passage of micro-size pathogens, such as the virus causing AIDS or HERPES. Such virus are known to be as small as 0.1 micrometer (0.001 millimeter), or about 250 times smaller than the length of the human sperm and at least 30 times smaller than the thickness of such sperm. The natural rubber membrane is comprised of a polymer matrix characterized by myriads of randomly distributed microsize openings or pores formed among polymer chains. Thus, although such natural rubber prophylactics have been found to be an effective barrier preventing the transmission of the larger sperm, there is no assurance that such devices are effective in preventing the transmission of such much smaller virus, and some testing to date has indicated to the contrary.
Additionally, the elastic membrane is usually cyclically stretched and relaxed in three dimensions during its intended use, resulting in repeated stressing of the membrane and reductions in its wall thickness, during such use. This action is believed to result in repeatedly enlarging and reducing the micro-size openings in the membrane, thereby increasing the probability of pathogens passing through the membrane.
Still further, despite extensive quality control testing of the prophylactics during manufacture, the membranes are not manufactured with absolutely uniform wall thicknesses, and therefore, during use different areas of the walls are not uniformly stressed nor uniformly stretched, resulting in "weaker spots" or areas and occasional bursting under severe stressing. The International Planned Parenthood Federation estimates that even from the best manufacturers, prophylactics have a bursting rate during use of 0.1% whereas those from the worst manufactured brands have a burst rate as high as 1%. Similar statistical data is not yet available, or has been published, with respect to the effectiveness of rubber prophylactics in preventing the transmission of virus, such as those causing AIDS and HERPES. It is widely believed, however, that presently available prophylactics are not very effective in preventing the transmission of such sexually transmitted diseases.
Before arriving at the present inventive prophylactics and methods, I first hypothesized that conventional prophylactics could be improved by providing a metal film or coating over the rubber membrane to effectively seal the micro-size openings therein, and therefore provide an improved barrier to the passage of such small virus. However, my tests showed that cyclically applied elastic stretching and relaxing of the coated rubber membrane, such as occurs during use, resulted in disrupting the metal layer, including the forming of cracks and fractures in the metal layer.